Select input channel

[maxiconil]

Hi, I'm using a multi input sound card (16 input channels). How can I select the channel I want to record? I mean, how can I set the input source of a stream?

Thanks

[scriptorian]

Hi.

The simple answer is that the underlying portaudio library captures all channels from a device, interleaved according to the selected sampleFormat option. If you wish to extract just one channel you will have to write some code to pick that channel's data from the interleaved stream that is returned.

Since the portaudio library offers a non-interleaved flag it would be possible to extend the naudiodon wrapper to offer some form of channel selection. The general case for this should probably involve a fair bit of work to support selecting and re-interleaving channels to the variety of common channel formats to make the required stream. I also note that the portaudio documentation warns that while it may be possible to open multiple streams on a device this is implementation defined.

Thanks, and good luck.